This, then, is Palm Sunday, the beginning of the final week of Jesus’s ministry on earth, and the day of His triumphant entry into Jerusalem. It was Passover week. Multitudes were arriving in Jerusalem for the Passover celebration. The significance of the timing will become apparent as the Passion of Christ unfolds.
Herewith the description of that long ago Sunday from the Gospel of John:
The Passover, a Jewish holy day, was near, and many country people arrived in Jerusalem several days early so that they could go through the cleansing ceremony before the Passover began. They wanted to see Jesus, and as they gossiped in the Temple, they asked each other, “What do you think? Will he come for the Passover?” Meanwhile the chief priests and Pharisees had publicly announced that anyone seeing Jesus must report him immediately so that they could arrest him.
Six days before the Passover ceremonies began, Jesus arrived in Bethany where Lazarus was—the man he had brought back to life. A banquet was prepared in Jesus’ honor. Martha served, and Lazarus sat at the table with him. Then Mary took a jar of costly perfume made from essence of nard, and anointed Jesus’ feet with it and wiped them with her hair. And the house was filled with fragrance.
The next day, the news that Jesus was on the way to Jerusalem swept through the city, and a huge crowd of Passover visitors took palm branches and went down the road to meet him, shouting, “The Savior! God bless the King of Israel! Hail to God’s Ambassador!”
Jesus rode along on a young donkey, fulfilling the prophecy that said: “Don’t be afraid of your King, people of Israel, for he will come to you meekly, sitting on a donkey’s colt!” (Zechariah 9:9)
(His disciples didn’t realize at the time that this was a fulfillment of prophecy; but after Jesus returned to his glory in heaven, then they noticed how many prophecies of Scripture had come true before their eyes.) John 11:55-57, 12:1-3, 12-16 TLB